It is about noticing the miracles around us, though you might search your whole life for them and not see them, they do, it seems, exist, and Plath seems to think the search for them is worth it- "the long wait for the angel,/ For that rare, random descent" can give meaning to life.

The irony is that you might miss these small miracles if you are looking for something transcendent- the beauty of life is found in "spasmodic...[t]ricks of radiance." For more information, see this summary: